Metamath Proof Explorer


Theorem fvffz0

Description: The function value of a function from a finite interval of nonnegative integers. (Contributed by AV, 13-Feb-2021)

Ref Expression
Assertion fvffz0 ⊢ N ∈ ℕ 0 ∧ I ∈ ℕ 0 ∧ I < N ∧ P : 0 … N ⟶ V → P ⁡ I ∈ V

Proof

Step Hyp Ref Expression
1 simpr ⊢ N ∈ ℕ 0 ∧ I ∈ ℕ 0 ∧ I < N ∧ P : 0 … N ⟶ V → P : 0 … N ⟶ V
2 simp2 ⊢ N ∈ ℕ 0 ∧ I ∈ ℕ 0 ∧ I < N → I ∈ ℕ 0
3 simp1 ⊢ N ∈ ℕ 0 ∧ I ∈ ℕ 0 ∧ I < N → N ∈ ℕ 0
4 nn0re ⊢ I ∈ ℕ 0 → I ∈ ℝ
5 nn0re ⊢ N ∈ ℕ 0 → N ∈ ℝ
6 ltle ⊢ I ∈ ℝ ∧ N ∈ ℝ → I < N → I ≤ N
7 4 5 6 syl2anr ⊢ N ∈ ℕ 0 ∧ I ∈ ℕ 0 → I < N → I ≤ N
8 7 3impia ⊢ N ∈ ℕ 0 ∧ I ∈ ℕ 0 ∧ I < N → I ≤ N
9 elfz2nn0 ⊢ I ∈ 0 … N ↔ I ∈ ℕ 0 ∧ N ∈ ℕ 0 ∧ I ≤ N
10 2 3 8 9 syl3anbrc ⊢ N ∈ ℕ 0 ∧ I ∈ ℕ 0 ∧ I < N → I ∈ 0 … N
11 10 adantr ⊢ N ∈ ℕ 0 ∧ I ∈ ℕ 0 ∧ I < N ∧ P : 0 … N ⟶ V → I ∈ 0 … N
12 1 11 ffvelcdmd ⊢ N ∈ ℕ 0 ∧ I ∈ ℕ 0 ∧ I < N ∧ P : 0 … N ⟶ V → P ⁡ I ∈ V